Cerussite

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Cerussite
Cerusitetsumeb2.jpg
Cerussite on malachite from the Tsumeb West mine in Namibia (size 7 cm × 5 cm)
General and classification
other names
  • Lead carbonate (formerly lead carbonate )
  • (white) lead spar (formerly lead spar )
  • White lead
  • White lead ore
chemical formula Pb [CO 3 ]
Mineral class
(and possibly department) 		Carbonates and nitrates (formerly carbonates, nitrates and borates)
System no. to Strunz
and to Dana 		5.AB.15 ( 8th edition : V / B.04)
01/14/03/04
Similar minerals Anglesite , phosgenite , barite
Crystallographic Data
Crystal system orthorhombic
Crystal class ; symbol orthorhombic-dipyramidal; 2 / m  2 / m  2 / m
Space group Pmcn (No. 62, position 5)Template: room group / 62.5
Lattice parameters a  = 5.18  Å ; b  = 8.49 Å; c  = 6.13 Å
Formula units Z  = 4
Frequent crystal faces {110}, {010}, {021}, {130}, {001}
Twinning {110}, mostly twins and triplets
Physical Properties
Mohs hardness 3 to 3.5
Density (g / cm 3 ) measured: 6.55 (2); calculated: 6.577
Cleavage good after {110} and {021}; indistinct on {010} and {012}
Break ; Tenacity clamshell; very brittle
colour colorless, white, light yellow, smoke to dark gray, black; colorless in transmitted light
Line color White
transparency translucent
shine Diamond shine to greasy shine
Crystal optics
Refractive indices n α  = 1.803
n β  = 2.074
n γ  = 2.076
Birefringence δ = 0.273
Optical character biaxial negative
Axis angle 2V = 8 ° to 14 ° (measured), 8 ° (calculated)
Other properties
Chemical behavior soluble in nitric acid with effervescence
Special features fluoresces yellowish under UV light

Cerussite , also known under its mining name white lead ore , is a frequently occurring mineral from the mineral class of " carbonates and nitrates " with the chemical composition Pb [CO 3 ] and is therefore chemically lead (II) carbonate .

Cerussite crystallizes in the orthorhombic crystal system and develops mostly prismatic, platy or pyramidal crystals , but also fine-grained to coarse, tufted, skeletal and powdery mineral aggregates . The formation of twins also creates pseudo-hexagonal crystal forms with an often lattice-like structure.

In its pure form, cerussite is colorless and transparent. However, due to multiple refraction due to lattice construction defects or polycrystalline formation, it can also appear white and, due to foreign admixtures, take on a light yellow, smoke to dark gray or black color, the transparency decreasing accordingly. However, its line color is always white.

With a Mohs hardness of 3 to 3.5, cerussite is one of the medium-hard minerals that, like the reference mineral calcite, can still be scratched with a copper coin.

Etymology and history

Lead carbonate has been known since ancient times, but only various uses of the mineral, including cosmetics, have been passed down.

In the miner's language , which has been handed down since the late Middle Ages , various names were used for lead carbonate, which were mainly based on the color of the mineral. The mineral was first mentioned in 1565 in the publication De omni rerum fossilium genere ... by Conrad Gessner , who named the mineral from the Italian province of Vicenza ( Vicentino ) after the Latin word cerussa and gave it the German name Bleyweiß . One of the early mentions is a paper published by Lazarus Ercker in 1580 , in which the mineral is described as white pley ertz .

In 1809 Abraham Gottlob Werner differentiated the “light lead spar” or white lead ore from the “dark lead spar” or black lead ore colored by admixtures . Friedrich Hausmann shortened these terms back to white lead and black lead in his Handbuch der Mineralogie in 1813 .

The name Cerussit, which is still valid today, was finally coined by Wilhelm von Haidinger in his Handbook of Determining Mineralogy, published in 1845, based on the Latin origin cerussa .

classification

In the outdated, but partly still in use 8th edition of the mineral classification according to Strunz , the cerussite belonged to the common mineral class of "carbonates, nitrates and borates" and there to the department of "anhydrous carbonates [CO 3 ] 2− without foreign anions ", where it together with alstonite , aragonite , barytocalcite , olekminsite , paralstonite , strontianite and withitherite the "aragonite group" with the system no. V / B.04 formed.

The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and is used by the International Mineralogical Association (IMA), assigns cerussite to the reduced class of "carbonates and nitrates" (the borates form a separate class here), but also to the Department of “Carbonates without additional anions; without H 2 O “. This is, however, further subdivided according to the element family of the cations involved , so that the mineral can be found according to its composition in the subsection " alkaline earth (and other M 2+ ) carbonates", where it is only found together with aragonite, strontianite and witherite "Aragonite group" with the system no. 5.AB.15 forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns cerussite, like the outdated Strunz system, to the common class of “carbonates, nitrates and borates” and there to the department of “anhydrous carbonates”. Here it is in the " aragonite group (Orthorhombic: Pmcn) " with the system no. 01/14/03 to be found in the sub-section "Anhydrous carbonates with simple formula A + CO 3 ".

Crystal structure

Cerussite crystallizes isotypically with aragonite orthorhombically in the space group Pmcn (space group no. 62, position 5) with the lattice parameters a  = 5.18  Å ; b  = 8.49 Å and c  = 6.13 Å as well as four formula units per unit cell . Template: room group / 62.5

properties

morphology

With over 80 known crystal forms and around 400 combinations, cerussite is one of the minerals with the most shapes. Prismatic and tabular shapes according to {010} and {001}, pyramidal shapes according to {111} and {021} and combinations according to {011} and {110} are predominant. Furthermore, various twin forms are known.

  • tabular with {001} and {010}

  • prismatic with {010} and {110}

  • Sextuplets

  • Angular twins according to {110}

  • Network-like growth due to cyclical twin formation

Chemical and physical properties

Cerussite in daylight (left) and UV light (right)

Cerussite occasionally shows yellow fluorescence under long-wave UV light as well as under cathode rays . In nitric acid , the mineral dissolves with a fizz, releasing carbon dioxide .

In front of the soldering tube , the mineral turns yellow and crackles, on carbon as a reducing agent a lead build-up occurs and metallic lead is produced.

Cerussite is stable under normal conditions (temperature 25 ° C, 1 atm , p CO 2 = 10 −4 atm). In nitric acid to Cerussite dissolves with effervescence. The solution is precipitated by adding sulfuric acid .

Compared to the chemically and colored similar minerals aragonite (Ca [CO 3 ]) and strontianite (Sr [CO 3 ]), cerussite has a significantly higher density . The visible, lively diamond luster , its high dispersion of 0.055 ( B – G ) and 0.033–0.050 (C – F), which even exceeds the diamond (B – G 0.044) known for it, and its significantly higher refraction are characteristic distinguishing features from Cerussit.

safety instructions

Due to its lead content and its solubility in acids , cerussite is considered toxic .

Cerussit has the CAS number 598-63-0. It is classified as an environmentally harmful substance that is harmful to organs and fertility .

Education and Locations

Cerussite is a typical mineral in the oxidation zone of carbonate of lead - deposits and arises among others from galena (galena). Here it occurs in company with minerals such as angelsite , smithsonite , malachite , hemimorphite and pyromorphite . It is often mixed with limonite or galena.

In connection with the latter, it likes to form whitish-gray to brown coatings called lead earth . By finely divided galena black colored Cerussite is Schwarzbleierz called.

Well-known sites include Broken Hill / New South Wales in Australia , Mechernich / Eifel and Clausthal-Zellerfeld / Harz in Germany , Mibladen in Morocco , Tsumeb in Namibia , Kabwe in Zambia , Iglesias in Sardinia , Stříbro in the Czech Republic , as well as Leadville and Flux Mine / Arizona in the USA . So far (as of 2010), Cerussite has been found at around 3,600 sites worldwide.

Well-known ore deposits include Leadville in Colorado (USA), Broken Hill in New South Wales (Australia) and Mechernich in North Rhine-Westphalia (Germany).

use

As a raw material

If it accumulates in so-called concentration deposits , among other things , cerussite can acquire local importance as lead ore . Well-known ore deposits include Leadville in Colorado (USA), Broken Hill in New South Wales (Australia) and Mechernich in North Rhine-Westphalia (Germany).

As cosmetics

For at least 3,500 years, cerussite from natural sources in the New Kingdom of Ancient Egypt has been added to cosmetics to lighten the skin . Cerussite was also synthesized in ancient Egypt as well as in ancient Greece so that it could be added to cosmetics regardless of raw material deposits. The recipe was retained in Europe into the Baroque era of the 17th century in order to produce "snow-white" skin. Recipe and manufacturing instructions from antiquity are no longer available.

Ancient mines for the extraction of silver Gangerze galena and Cerussite up to 125 meters below ground near the other were in Iran, Parthian - Sasanian fixation Qale Kujek (recent mining settlement Nakhlak) driven (in 127 feet of water is the water table).

As a gem

"Light of the Desert" on display at the Royal Ontario Museum

Cerussite is unsuitable for commercial use as a gem stone , despite its extreme gloss, its higher dispersion even compared to diamond and its sometimes water-clear varieties, as it is difficult to grind due to its low hardness and great brittleness on the one hand and very sensitive to the influence of heat on the other as well as all work techniques for jewelry production. For collectors and museums, however, it is occasionally offered in various cut shapes. The cerussite, known as the "Light of the Desert" and with a weight of 896 carats, is the largest polished cerussite to date. The rough stone was discovered in Tsumeb (Namibia), brought into its present form by the gemstone cutter Maria Atkinson in Sedona (Arizona) and then given as a gift from the Louise Hawley Stone Charitable Trust to the Royal Ontario Museum in Ontario.

See also

literature

Web links

Commons : Cerussite  - collection of images, videos and audio files

Individual evidence

  1. ↑ Webmineral - Cerussite (English)
  2. ^ A b c Hugo Strunz , Ernest H. Nickel : Strunz Mineralogical Tables. Chemical-structural Mineral Classification System . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p.  288 .
  3. ↑ a b c d e f Cerussite . In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America . 2001 ( handbookofmineralogy.org [PDF; 66  kB ; accessed on July 2, 2018]).
  4. ↑ a b c d e Mindat - Cerussite (English)
  5. ↑ C. Gesner: De omni rerum fossilium genere, gemmis, lapidibus metallis, et huiusmodi, libri aliquot, plerique nunc primum editi . Tiguri 1565 ( available online at digital.slub-dresden.de [accessed on July 2, 2018]).
  6. ↑ Hans Lüschen: The names of the stones. The mineral kingdom in the mirror of language . 2nd Edition. Ott Verlag, Thun 1979, ISBN 3-7225-6265-1 , p. 342 (quoted from the description of the most precious mineral ores and mine types. 2nd edition, Frankfurt am Main 1580).
  7. Jump up ↑ Abraham Gottlob Werner : Abraham Gottlob Werner's last mineral system: from his estate on the order of the mining authority . Graz and Gerlach, 1809, p.  41 ( limited preview in Google Book search).
  8. ↑ Joh. Friedr. Ludw. Hausmann: Handbook of Mineralogy . tape 1 . Bandenhoeck and Ruprecht, Göttingen 1813, p. 1107, 1111 ( limited preview in Google Book search).
  9. ^ Wilhelm Haidinger: Handbook of determining mineralogy . Braumüller & Seidel, Vienna 1845, p. 503 ( limited preview in Google Book search).
  10. ↑ a b Martin Okrusch, Siegfried Matthes: Mineralogie. An introduction to special mineralogy, petrology and geology . 7th, completely revised and updated edition. Springer, Berlin [a. a.] 2005, ISBN 3-540-23812-3 , pp. 66 .
  11. ↑ a b Hans Jürgen Rösler : Textbook of Mineralogy . 4th revised and expanded edition. German publishing house for basic industry (VEB), Leipzig 1987, ISBN 3-342-00288-3 , p.  710-711 .
  12. ↑ a b c Helmut Schrätze , Karl-Ludwig Weiner : Mineralogie. A textbook on a systematic basis . de Gruyter, Berlin; New York 1981, ISBN 3-11-006823-0 , pp.  540-542 .
  13. ^ Friedrich Klockmann : Klockmanns textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke, Stuttgart 1978, ISBN 3-432-82986-8 , pp.  576 (first edition: 1891).
  14. ^ Walter Schumann: Precious stones and gemstones. All kinds and varieties. 1900 unique pieces . 16th revised edition. BLV Verlag, Munich 2014, ISBN 978-3-8354-1171-5 , pp. 42, 216 .
  15. ^ Walter Schumann: Precious stones and gemstones. All kinds and varieties. 1900 unique pieces . 16th revised edition. BLV Verlag, Munich 2014, ISBN 978-3-8354-1171-5 , pp. 42, 86 .
  16. ↑ Cerussite, naturally occuring mineral. Safety data sheet according to 1907/2006 / EG, Article 31. In: alfa.com. Alfa Aesar, October 13, 2006, accessed July 2, 2018 .
  17. ↑ Find location list for Cerussite in the Mineralienatlas and in Mindat
  18. ↑ Lucile Beck, Ingrid Caffy, Emmanuelle Delqué-Količ, Christophe Moreau, Jean-Pascal Dumoulin, Marion Perron, Hélène Guichard, Violaine Jeammet: Absolute dating of lead carbonates in ancient cosmetics by radiocarbon . In: Communications Chemistry . tape 1 , no. 1 , 2018, p. 34 , doi : 10.1038 / s42004-018-0034-y ( nature.com [PDF; 813 kB ; accessed on July 2, 2018]).
  19. ↑ Torsten Purle: Everyday - Mineral Cosmetics / Cosmetics from Minerals. In: steine-und-minerale.de. June 4, 2018, accessed July 1, 2018 .
  20. ↑ Raimar W. Kory, Daniel Steiniger: Thoughts on Sasanid inland and deep sea shipping with special consideration of local and long-distance maritime trade . In: Daniel Büchner, Freiburg Institute for Paleoscientific Studies (Hrsg.): Studies in memoriam Wilhelm Schüle (= Claus Dobiat, Klaus Leidorf [Hrsg.]: International Archeology - Studia honoraria Ort = Rahden / Westf. ). 2001, ISBN 978-3-89646-391-3 , ISSN  1433-4194 , pp. 255 ( available online at academia.edu [accessed July 2, 2018]).
  21. ↑ Gem etiquette from Prof. Leopold Rössler at beyars.com
  22. ↑ World's Largest Cerrussite on YouTube (including inclusion of the billboard with size indication at 14th second)
  23. ^ Video from the Royal Ontario Museum about the "Light of the Desert" on YouTube
  24. ↑ Royal Ontario Museum (ROM) - Cerussite "Light of the Desert" ( Memento from September 4, 2017 in the Internet Archive )